An overlock sewing machine is provided with multiple loopers. There is a need to thread a different looper thread through each of the loopers, which requires a troublesome threading operation.
The invention of Japanese Patent H06-277383 discloses an apparatus configured to supply a thread using compressed air such that it reaches a looper blade tip having a hollow structure.
With such an air pressure threading apparatus using compressed air according to conventional techniques, there is a need to pinch a thread with the fingers so as to insert the thread into a thread inserting hole.
FIG. 20 is a diagram showing a step according to such conventional techniques in which a thread is inserted into such a thread inserting hole with the fingers.
With conventional techniques, for example, it is necessary to pinch a thread 6 with the fingers and carefully insert a thread tip 6a into an upper looper thread inserting hole 4 or otherwise a lower looper thread inserting hole 5.